It shouldn't be a shock that BMW is working on a convertible version of the M4. Not only have we caught it testing twice, but this is an automaker that seems willing to build a vehicle for nearly every buyer's needs. Evo claims that the high-performance droptop is going to debut at this year's Goodwood Festival of Speed in England from June 26-29.

Judging from the spy shots we've seen, the M4 Convertible will consist of a retractable hard top like the 4 Series cabrio. Other than the roof, there aren't expected to be many changes from the coupe. The engine will be the same turbocharged, 3.0-liter inline six-cylinder engine, but the added weight of the roof and its mechanism may take a small bite out of performance.